Real Wage Rigidities and the New Keynesian Model
指出标准新凯恩斯模型中稳定通胀与稳定产出缺口无冲突的“神圣巧合”源于缺乏实际刚性，引入实际工资刚性后央行面临权衡，且模型能更好解释通胀与失业的动态关系。
Most central banks perceive a trade‐off between stabilizing inflation and stabilizing the gap between output and desired output. However, the standard new Keynesian framework implies no such trade‐off. In that framework, stabilizing inflation is equivalent to stabilizing the welfare‐relevant output gap. In this paper, we argue that this property of the new Keynesian framework, which we call the divine coincidence , is due to a special feature of the model: the absence of nontrivial real imperfections. We focus on one such real imperfection, namely, real wage rigidities. When the baseline new Keynesian model is extended to allow for real wage rigidities, the divine coincidence disappears, and central banks indeed face a trade‐off between stabilizing inflation and stabilizing the welfare‐relevant output gap. We show that not only does the extended model have more realistic normative implications, but it also has appealing positive properties. In particular, it provides a natural interpretation for the dynamic inflation–unemployment relation found in the data.